This invention relates to a method and apparatus for assembling and securing a length of flexible tubing having a predetermined internal diameter to a cylindrical member having an external diameter larger than the predetermined internal diameter of the tubing. More particularly, it relates to a method and apparatus for securing a length of flexible tubing such as a plastic or elastomer sleeve to a cylindrical part, such for example as an assembly of a spray can, wherein the outside diameter of the cylindrically shaped member is larger than the internal diameter of the sleeve. This is first accomplished by first expanding the flexible tubing mechanically to the desired interior diameter and then freezing it at this expanded size by spraying it with a cooling media such as liquid nitrogen or equivalent. The flexible tubing then is easily placed over the cylindrically shaped member and when the expanded frozen tubing warms and returns to its original configuration, it generates a tight pressure bond to the inserted cylindrical part without the use of solvents or adhesives.
While the prior art has disclosed various ways for solventless assembly of a flexible tubing to a component they have left something to be desired. Such prior art systems have in general used jaws which are inserted into the tubing and then move apart to create a stretching of the tubing. This is caused by the jaws opening in a non-parallel type movement thus creating a greater stretching of the tubing at the mouth of the jaws then at the inner end. This problem is created because the jaws can only be supported at one end. One attempt to overcome this problem in the prior art has been to use a relatively elaborate guiding arrangement to radially direct the jaw members from a closed position to a position spaced therefrom while maintaining a parallel relationship with respect to the jaw members. Moreover, it is limited as to the length of tubing that can be stretched and the shape of the stretched tubing does not correspond to the part to be inserted therein.
The disadvantages of the prior art are overcome by the present invention which provides for securing a length of flexible tubing having a predetermined internal diameter to a member having an external diameter larger than the predetermined internal diameter of the tubing in an efficient and relatively inexpensive manner.